1. Field of the Invention
The present invention generally relates to a device for offloading a portion of a patient's weight during gait training.
2. Discussion of the Related Art
Partial weight bearing gait training is a method of training and rehabilitating a patient that has completely lost or has suffered a reduced ability to ambulate. During training the weight of the patient is partially supported by an unweighing device. Specifically, the patient is able to undergo physical training such as learning or relearning to walk with the aid of a treadmill without having to support his entire body weight which would otherwise impose a significant obstacle during gait training. As gait training therapy progresses, the amount of body weight that is supported or off weighed may be gradually reduced.
Unweighing body support systems or weight offloading systems are commonly used during locomotion on a treadmill in the treatment of patients with neurological deficits and other clinical conditions such as lower extremity fractures, osteoarthritis, and lower extremity amputations. A patient suffering the effects of neurological trauma or disease that curtails the patient's ability to ambulate bearing his full body weight can gain gait motion with the aid of an unweighing system, assisted or unassisted, in order to retain muscle tone and gain strength. In addition, patients, especially athletes, can resume training earlier that would have been possible without the aid of weight offloading devices.
Weight offloading systems use a variety of methods to support a portion of a patient's body weight. Many systems in use today, employ a harness that is worn by the patient and is connected to overhead cables and/or ropes that apply an upward physical force to reduce a portion of the patient's body weight. In some systems, the supporting cables or ropes are affixed to a framework wherein the frame or a portion of the frame is upwardly adjusted until the force develops in the rope. In other systems, ropes run over a series of pulleys and weights are added to the ropes to develop a tension force in the rope which off loads the weight of the patient. Many of these systems measure the force applied to the patient through the rope or cable, which magnitude of the force is then displayed.
There are several different commercially available weight offloading gait training devices. In some systems, the frame is adjusted upwards to tension a rope that is attached to a harness worn by the patient. In these systems, however, there is no up or down movement without the load varying widely or disappearing. Some systems of this type add springs of various lengths to the rope in order to allow for a small amount of movement, but the load still varies widely, i.e., the movement of the patient will cause a substantial variation in the magnitude of the lifting force applied to the patient. In addition, these units have limited ranges. In other systems the rope is manually pulled. Although such manual systems allow a larger adjustment range, the movement of the patient still presents a loading problem. While other units use weights to adjust the tension in the rope, it is difficult to apply the load, and mobility of the unit is impracticable due to the swinging of the weights and difficulty to push them. Pneumatic units apply a more constant force and have greater ranges, but because such units require an air compressor they are not mobile. In addition to the various drawbacks associated with the particular systems, such systems are generally heavy and expensive.
Other drawbacks of known weight offloading gait training systems include the lack of a place for the therapist to sit while administering gait therapy, lack of accurately reading the unweighing load, frame sizes that do not accommodate a sufficient number of patient sizes. In addition, some available systems are restrictive to the extent a patient cannot easily change directions, and/or are not suitable to aid with assisting a patient out of a wheelchair.
What is needed is an apparatus to offload a portion of a patient's weight during gait training that allows the patient to move up and down during the natural motion of walking and running and still apply a reasonable constant force.
What is also needed is an apparatus to offload a portion of a patient's weight during gait training and catches the patient if there is too much movement or if the patient is unable to support even their reduced weight.
What is also needed is an apparatus to offload a portion of a patient's weight during gait training wherein the force should be relatively easy to apply.
What is further needed is an apparatus to offload a portion of a patient's weight during gait training that is mobile, lightweight and easy for the patient to push so the patient can ambulate over a floor surface.
What is further needed is an apparatus to offload a patient's weight during gait training that enables the patient to reverse his direction easily while pushing the unit without having to turn around a bulky system within a confined space.
Yet another need is an apparatus to offload a patient's weight during gait training allowing the rope a large adjustment range to accommodate different sized patients and having the force on the rope assist the patient rising out of a wheel chair or off a treatment table.
Other features and advantages of the present invention will become apparent from the following detailed description of the invention with reference to the accompanying drawings.